Delaying kindergarten enrollment for one year shows significant mental health benefits for children, according to a Stanford University study published by the National Bureau of Economic Research. Reviewing results from a mental health survey completed by more than 35,000 Danish parents, the researchers saw that youngsters held back from kindergarten for as little as one year showed a 73 percent reduction in inattentiveness and hyperactivity for an average child at age 11, compared to children enrolled the year earlier.

Measuring inattentiveness and hyperactivity reflect a child’s ability to self-regulate. The generally accepted theory is that young people that are able to stay focused, sit still and pay attention longer tend to do much better in school.

“This is some of the most convincing evidence we’ve seen to support what U.S. parents and policymakers have already been doing—choosing to delay entry into kindergarten,” says Stanford Graduate School of Education Professor Thomas S. Dee. In addition to improved mental health, children with later kindergarten enrollment dates also exhibited superior emotional and social skills.

The number of U.S. children entering kindergarten at age 6 instead of 5 has progressively increased to about 20 percent, according to the study. Many parents are opting to delay kindergarten enrollment for a year to give their children a leg up in physical and emotional maturity and social skills.